Manually operable crimping tools



Dec. 28, 1965 w. WALTON ETAL 3,225,583

MANUALLY OPERABLE CRIMPING TOOLS 3 Sheets-Sheet 1 Filed May 29, 1962 Dec. 28, 965 w. WALTON ETAL 3,225,583

MANUALLY OPERABLE CRIMPING TOOLS 5 Sheets-Sheet 2 Filed May 29, 1962 Dec. 28, 1965 w. WALTON ETAL 3,225,583

MANUALLY OPERABLE CRIMPING TOOLS Filed May 29, 1962 3 Sheets-Sheet S United States Patent Ofi 3,225,583 Patented Dec. 28, 1965 3,225,583 MANUALLY OPERABLE CRIIVIPING TOOLS William Walton, Swindon, and Arthur Manthorp Faulkner, Highworth, England, assignors to The Plessey Company Limited, Ilford, England, a company of Great Britain Filed May 29, 1962, Ser. No. 205,817 Claims priority, application Great Britain, June 2, 1961, 19,986/61 10 Claims. (Cl. 72-412) This invention relates to manually operable crimping tools and has for an object to provide an improved crimping tool in which a crimping operation requiring a considerable amount of total energy expenditure can be effected by a hand tool adapted for one handed operation and not requiring any external power supply. A further object is to provide a crimping tool of this kind in which the final pressure applied to the crirnped connection is independent of the operators manual effort. It is applicable with particular advantage to crimping tools of the kind in which the geometrical shape of the aperture accommodating the parts to be crimped remains substantially unaltered during the crimping operation, and when applied to the crimping tools of that kind enables the crimping pressure to be automatically adjusted according to the diameter of the parts to be crimped. A still further object of the invention is the provision of a hand operated crimping tool which prevents the production of faulty crimps by ensuring that in each crimping operation a crimping force is supplied whose magnitude is determined only by the dimensions of the crimp.

According to the present invention the movement of the crimping jaws during the crimping operation is arranged to be produced by the release of energy from an energy store which between crimping operations is chargeable by manual means. The store conveniently consists of a spring which is tensioned during the opening of the crimping jaws. The spring may be a metal spring and is preferably a multi-disc spring, which permits ready realisation of a spring of comparatively small dimensions having a high spring rate. The spring is combined with automatic retaining means permitting the loading of the spring to be effected in stages, for example by means of a hydraulic piston device which through suitable valve means co-operates with a hand-operated piston pump.

FIGURES 1 to 4 of the drawing accompanying the specification illustrate one embodiment of the invention, in which the crimping tool is of the kind described in our co-pending U.S.A. application No. 111,866 permitting the geometrical shape of the aperture formed by the crimping jaws to remain constant over a relatively wide range.

FIGURE 1 is a sectional side elevation of the device,

FIGURE 2 is a rear elevation,

FIGURE 3 is a fragmentary plan view, partly in section on line 33 of FIGURE 2, and

FIGURE 4 is a fragmentary section on line 44 of FIGURE 1.

FIGURES 5 and 6 of the accompanying drawing are respectively a sectional elevation and a cross-section on line 66 of FIGURE 5 of a modified embodiment.

Referring now to FIGURES 1 to 4, the crimping tool has a body 1, to which a frame member 2 is attached by screws 9. In the frame 2 a number of crimping jaws 3 are guided, substantially in the manner described in our said co-pending application, so as to enclose between the jaws a crimping aperture which, upon movement of one of the jaws in a predetermined direction, progressively decreases in size without appreciably altering its geometrical shape. A return spring 4 is provided for opening the crimpings jaws after the crimping operation has been completed. Guided in the body 1 is a thrust pin 5 which is adapted to act upon the said jaws to effect the crimping operation, and which is connected to a piston member 6 which is slidable axially of the thrust pin 5 in a cylinder bore 7 of a housing 8 which is integral with the body 1. The cylinder bore 7 constitutes a container which is closed at one end by the body 1 and at its other end by a plug 10, and a multi-disc compression spring 11, centered on a guide rod 12, is interposed between the piston member 6 and the plug 10 within the cylinder bore to constitute an energy store having inherent damping. The remainder of the bore is adapted to be filled with a hydraulic liquid, and the chambers formed between the piston and the respective ends of the bore 7 are interconnected through a passage including bores 13 and 14 and the bore 15 of a pump cylinder member 16 accommodated in a further bore of the housing 8, a non-return valve 17 being arranged to co-operate with one end of the cylinder bore 15 for retaining the charge in the energy store. A ram-type piston 18 slides in the cylinder bore 15 and, as shown in FIG. 3, is connected by a swivel connection to a cross head 76 carried by link rods 19 pivoted by screw pivots to one end of a hand lever 20. The latter, as shown in FIGURE 1, is pivoted by a fulcrum pin 21 in a pistol-grip portion 22 integral with the housing 8. A spring 23 biases the lever 20 to move out of the pistol grip 22, thereby moving the piston 18 away from the valve 17 and the piston 18 has an axial end bore 70 which penetrates into a cross bore 71 at a distance from the end of the ram piston. When the piston is in this retracted position, the cross bore 71 communicates with a cross bore 73 in the cylinder member 16, leading to an annular chamber 72 which is connected by the bore 14 to that part of the housing bore 7 which contains the multi-disc spring 11, which serves as a reservoir for hydraulic liquid. Liquid from this reservoir can now flow into the part of the cylinder bore 15 between piston 18 and non-return valve 17. When the lever 20 is then pressed to move it towards or into the pistol grip 22, the piston 18 will force liquid from the space between the piston member 6 and plug 10 into the space between piston 6 and body 1, thereby moving the piston member 6 to compress the spring 11. The non-return valve 17 will prevent liquid from flowing back, under the action of the spring 11, when the hand lever 20 is subsequently released and returned by the spring 23 to its projecting position, causing the piston 18 to admit a further quantity of liquid from the reservoir chamber between piston 6 and the plug 10 into the pump cylinder 15. A further movement of the hand lever 20 towards the pistol grip handle 22 will therefore simliarly produce additional compression of the spring 11, and this operation can be repeated until the jaws 3 have opened sufficiently to admit the parts to be crimped. The spring 11 will be loaded at that time by a force which is substantially proportional to the outward movement of the crimping jaws and thus to the diameter or an equivalent transverse dimension of the parts to be crimped. These parts can now be inserted between the crimping jaws. In order to perform thereafter the crimping operation, it is necessary to permit liquid from the chamber between piston member 6 and body 1 to return to the chamber between piston 6 and plug 10. Therefore according to a feature of the invention a movement of the lever 20 into the handle 22 beyond the normal end position of the pumping stroke causes the end of piston 18 to strike the non-return valve 17 and lift it from its seat. The pump cylinder member is further provided with a cross bore 74 of the cylinder member 16 which, similarly to the bore 73, communicates through bore 14 with that part of the housing bore 7 which contains the compression spring 11. Due to this movement of the lever 20 beyond the normal end position of the pumping stroke, the cross bore 71 of piston 18 comes into alignment with this cross bore 74, so that as the piston member 6 is moved by the spring 11, liquid from the part of the housing bore 7 at the other side of the piston 6 can now return through pasage 13, the open non-return valve 17, passages 70, 71 and 74, which as shown are of small diameter and therefore have a restricting action on the How, and bore 14 to the reservoir provided in that part of the bore 7 which contains the multi-disc spring 11. In order to prevent movement of the lever 20 to this position during the loading of the spring 11 constituting the power reservoir and thus to prevent premature discharge of the power reservoir, the lever 20 carries an adjustable stop pin 24 which normally terminates the inward movement of the lever 20 by contact with a raised portion 25 of the periphery of a stop cam 26 which is fixed on a rotatable pin 27. This pin is journalled in the pistol-grip handle 22 and carries a release latch 28 outside the said handle. By means of the latch 28 the cam 26 can be turned, after the reservoir has been adequately charged, to a position in which the abutment pin 24 faces a portion 29 of the cam periphery which has a smaller distance from the axis of the rotatable pin than the portion 25, thus permitting the hand lever 20 to be moved inwardly of the pistol grip 22 sufficiently to cause the piston 18 to raise the non-return valve 17. Preferably the stop cam 26 is further equipped with a pair of dogs 30 which at an intermediate position of the latch 28 engage a groove 31 or equivalent lateral recesses of the abutment pin 24. In this manner the hand lever 20 may, after charging of the power reservoir, be retained, before the crimping operation proper, in a position corresponding approximately to the end of the normal pumping stroke, thus avoiding the necessity of carrying out a further pumping stroke, involving unnecessary effort, after the insertion of the parts to be crimped, before the valve 17 can be opened to commence the crimping stroke of pin 5.

In the illustrated embodiment the guide rod 12 is secured in the piston member 6 and slides in a blind bore 78 of the plug member 10, the end of this bore communicating with the reservoir space between plug and piston member 6 through a bore 32, and a pressurized buffer reservoir 33, FIG. 2 for hydraulic liquid is arranged to communicate by a passage 34 with the bore 7 between the piston member 6 and the plug 10 to compensate for the excess in cross section of the guide rod 12 in the chamber between the piston member 6 and the body 1 over the thrust pin 5 in the chamber at the opposite side of the piston member 6.

The embodiment described with reference to FIGURES 1 to 4 may be modified in a number of details without exceeding the scope of the invention, and FIGURES 5 and 6 illustrate by way of example a modified construction which is both more compact and of simpler construction than the embodiment described with reference to FIG- URES 1 to 4. Equal reference numbers in FIGURES S and 6 refer to parts which are identical or substantially identical With those illustrated in FIGURES 1 to 4, and reference is made to the description of those figures for their operation.

An important modification relates to the arrangement of the charging pump to its actuating lever. Instead of an actuating lever 20 co-operating with a pistol grip projecting laterally from the cylinder housing 8, a hand lever 50 is employed which extends along the housing 8 and is pivoted to it by a pin 51' arranged at the rear end of the housing 8, away from the frame member 2 and diametrically opposite to the side of the housing 8 along which the lever 50 extends. A ram piston, bearing the reference number 48, and generally similar to the ram piston 18 of FIGURES 1 to 4, is accommodated in a cylinder constituted by an axial bore 45 of a guide rod 42 for the piston 6, this guide rod being firmly anchored in the outer end member 40 of the cylinder housing while the piston 6 is free to slide on the guide rod 42. The piston 6 is coupled to the end of the thrust pin 5 by a thrust ring 52 which rests on an internal shoulder of the piston, and which on its back surface carries a plug member 53 supporting the spring of the non-return valve 17. The ram piston 48 is urged away from the thrust member 5 by a spring 43 which acts on a head 54 provided at the end of a reduced-diameter stem 79 of the ram 48, and the lever 50 is arranged to act on the head 54 through a roller 49 which is adjustable by being carried by an arm 55, pivoted on the same pin 51 as the lever 50 having an adjustable set pin 56 co-operating with a thrust pad 57 of the lever 50. Fixed to the end of the arm 50 which is nearest to the frame 2, is a headed locking pin 58 which, during normal pumping operation to charge the spring 11, terminates the inward stroke of the lever 50 by striking a toe 59 of a locking ring 60, 61 which performs the function of cam 26 of FIGURE 1. Thus, the movement of the ram 48 is normally stopped before it strikes the non-return valve 17. The portion 61 of the locking ring 60 forms a shell having an aperture 62 suitably positioned and sufficiently wide for the head 58 to pass freely through it. A tab 63 enables the ring to be turned from the position just described first to a crimping position, in which the pin 58 faces another similar aperture 64, in which it is, however clear of the toe 59, thus allowing the lever 50 to be moved further so as to cause the ram 48 to lift the non-return valve 17 from its seat, thus similarly as in FIGURE 1 releasing the liquid under pressure trapped between the piston 6 and the body member 1, allowing it to return to the reservoir chamber between the piston 6 and the outer end member 40, and the crimping operation is then performed by the stored energy of the spring 11. The apertures 62 and 64 of the ring portion 61 are connected by a relatively narrow slot 65 wide enough to clear the stem of the pin 58 but not its head, so that when the ring member 60, 61 and the lever 50 are in the illustrated central position, the lever 50 is locked in that position. A pin 66, co-operating with a slot 67 in the inner ring member 60, serves to limit the movement of the ring 60, 61 in the range of these three positions, in each of which a ball catch 68 is arranged to engage one of three rests 69 in the body 1.

What we claim is:

1. In a manually operable crimping tool having a main body including means for supporting at least two crimping jaws movable relative to each other, the combination comprising elastic means mounted in said body to form a damped chargeable energy store, reciprocatory storecharging means supported in said body and operatively connected to said elastic means, said store-charging means being manually operable to deform said elastic means in step-by-step fashion for charging the store, retaining means automatically locking the store against discharge from any one of a plurality of degrees of charging, means manually operable to release said elastic means by rendering said retaining means inoperative, and means coupling at least one of said crimping jaws to said elastic means for moving such jaw towards another of said crimping jaws under the elastic force released by said elastic means when the retaining means has been rendered inoperative.

2. A crimping tool as claimed in claim 1, which includes means for limiting the rate of discharge of the energy store.

3. A crimping tool as claimed in claim 1, including a pressure container, a piston member forming a movable partition in said container, said piston member being supported at one side against said elastic means, a manually operable piston pump having a delivery line equipped with a non-return valve normally preventing return flow from said container to the piston pump and leading to said part of the pressure container to the part located at the other side of the piston member, and means manually operable to open a restricted low pressure outlet from said part of the container.

4. A crimping tool as claimed in claim 1, wherein the elastic means is constituted by a multi-disc metal spring which is compressed during the opening of the crimping aws.

5. A crimping tool as claimed in claim 1, including a pressure container, a piston member forming a movable partition in said container, a compression spring constituting the elastic means, said piston member being supported at one side against said spring, a manually operable piston pump having a delivery passage equipped with a non-return valve normally preventing return flow from said container to the piston pump, said passage leading to the part of said pressure container that is located at the other side of the piston member, and means manually operable to open a low-pressure outlet from the said part of the container.

6. A crimping tool as claimed in claim 5, wherein the manually operable piston pump has a piston manually operable to execute delivery strokes separated by return strokes and is arranged to withdraw from the other part of the container and deliver it to the delivery passage, the piston being arranged, when such delivery stroke is extended to a predetermined position, to lift the nonreturn valve from its seat and establish communication between the delivery passage and said other part of the container, releasable stop means being provided for normally terminating the delivery stroke short of said predetermined position.

7. A crimping tool as claimed in claim 5, wherein said piston member is of annular shape, and wherein said piston pump includes a pump cylinder arranged in said container to form a guide rod on which said annular piston member is slidably supported.

8. A crimping tool as claimed in claim 7 further ineluding an operating hand lever extending along the container.

9. A crimping tool as claimed hi claim 1, wherein the main body includes a handle portion and the reciprocatory store-charging means includes a hand lever pivoted at one of its ends to the main body for movement between a first position in which the hand lever is substantially parallel and closely adjacent to the "handle portion, and a second position in which the hand lever extends at an acute angle from the handle portion, and spring means biasing the hand lever to the second position, the arrangement being such that movement of the lever from the second towards the first said position acts to charge the store, while the lever is free to move in the opposite direction Without affecting such discharge.

19. A crimping tool as claimed in claim 9, wherein the elastic means comprises a compression spring, and where in the handle portion extends from the main body substantially perpendicularly to the direction in which said spring is compressed.

References Cited by the Examiner UNITED STATES PATENTS 1,874,460 8/1932 Cox 8152.35 X 2,004,459 6/1935 Boehnke 81-15 2,235,591 3/1941 Ruiter 81-52.35 X 2,375,734 5/1945 Montgomery et al. 279-2 2,721,491 10/1955 Klitzke 81-52.3 2,729,063 1/1956 Hoadley -52 2,821,877 2/1958 Swanson 81-15 3,085,813 4/1963 Sampson.

CHARLES W. LANHAM, Primary Examiner.

WILLIAM FELDMAN, MILTON S. MEHR, Examiners. 

1. IN MANUALLY OPERABLE CRIMPING TOOL HAVING A MAIN BODY INCLUDING MEANS FOR SUPPORTING AT LEAST TWO CRIMPING JAWS MOVABLE RELATIVE TO EACH OTHER, THE COMBINATION COMPRISING ELASTIC MEANS MOUNTED IN SAID BODY TO FORM A DAMPED CHARGEABLE ENERGY STORE, RECIPROCATORY STORECHARGING MEANS SUPPORTED IN SAID BODY AND OPERATIVELY CONNECTED TO SAID ELASTIC MEANS, SAID STORE-CHARGING MEANS BEING MANUALLY OPERABLE TO DEFORM SAID ELASTIC MEANS IN STEP-BY-STEP FASHION FOR CHARGING THE STORE, RETAINING MEANS AUTOMATICALLY LOCKING THE STORE AGAINST DISCHARGE FROM ANY ONE OF A PLURALITY OF DEGREES OF CHARGING, MEANS MANUALLY OPERABLE TO RELEASE SAID ELASTIC MEANS BY REN- 